As the son of Poseidon, Percy Jackson wakes up to the reality of his life that is a chaotic world of monsters, gods, and demigods. He realizes that he is followed by two snake-haired women who are hard to get rid of. He travels to the camp for the half-bloods which confuses him as he does not understand his purpose yet.
He meets the wolf Lupa who informs him about his true identity, that of a demigod and teaches him how to use his pocket sword to fight. Still, Percy’s mind does not give him any clear clues about his past and the vision is still blurred. The only thing the reader is sure about is that the quest followed by Percy and other demigods Hazel and Frank – the one that began in the previous books of the series – is still on. The search for the Prophesy of Seven has to be accomplished at any cost. They cannot fail in their mission or else many lives and the world might be on the verge of complete destruction.